Today a message will be going out to all Steam users. According to Valve, the Steam forums were compromised on November 6th, but further investigation revealed that the damage went further than just the forums: The Steam user database was also compromised. The email from Valve’s founder Gabe Newell:
Dear Steam Users and Steam Forum Users,
Our Steam forums were defaced on the evening of Sunday, November 6. We began investigating and found that the intrusion goes beyond the Steam forums.
We learned that intruders obtained access to a Steam database in addition to the forums. This database contained information including user names, hashed and salted passwords, game purchases, email addresses, billing addresses and encrypted credit card information. We do not have evidence that encrypted credit card numbers or personally identifying information were taken by the intruders, or that the protection on credit card numbers or passwords was cracked. We are still investigating.
We don’t have evidence of credit card misuse at this time. Nonetheless you should watch your credit card activity and statements closely.
While we only know of a few forum accounts that have been compromised, all forum users will be required to change their passwords the next time they login. If you have used your Steam forum password on other accounts you should change those passwords as well.
We do not know of any compromised Steam accounts, so we are not planning to force a change of Steam account passwords (which are separate from forum passwords). However, it wouldn’t be a bad idea to change that as well, especially if it is the same as your Steam forum account password.
We will reopen the forums as soon as we can.
I am truly sorry this happened, and I apologize for the inconvenience.
While there is no evidence that passwords and credit card information have been compromised, with the state of encryption cracking, it should only be a matter of time (and horsepower). This would be a very, very good time to change your Steam passwords (SideQuesting has an easy-to-follow guide), watch your credit card statements, and enable two-factor authentication on your Steam account (and your Google account as well, if you use Gmail for anything). To enable two-factor authentication in Steam, go to “Settings” and you’ll find instructions under the “Account” section.